He got rid of evidence so that the police wouldn't figure out Petra had been in that room with Zaz. How is that him doing his job?

Gloone: "refusing to bed her and getting so heroically drunk"

I don't think Moriarty is even capable of love. What she did make clear was that he is the only one who has surprised her, who can challenge her, when no one else ever has.  She is fascinated with his mind, not in love with him.

Too stupid and naive to survive and yet she's still just that, surviving. While so many have fallen and will fall, she's still there. Stay pressed.

What happened to him is a mystery so I assume it will come up again in the future

She's at her lowest, needing to feel loved, who else would she turn to than the only man who loves her unconditionally?